Move over Halloween – the 31 October officially has a new name – Dark Matter Day.

On Tuesday 31 October thousands of people from all over the world joined in a global celebration of dark matter, one of the biggest mysteries of our Universe. On Dark Matter Day 24 countries marked the day with events. In the UK more than 20 events were held, including one in Parliament and many run by the UK’s dark matter researchers. The UK is a world leader of dark matter research.

Dark matter is a huge part of the Universe that scientists’ calculations tell us exists, but that has never been observed. Yet, together with dark energy, scientists believe it makes up 95 percent of the total universe. What we can see, and the matter that scientists can account for is just five percent of the Universe, the rest is a mystery. You can find out more on our dark matter pages.

To highlight the international effort to find dark matter, Dark Matter Day was created by the Interactions collaboration, a global network of particle physics communicators.

Events were held all over the world, in the US, Canada, France, Brazil and Norway to name a few. In the UK events on Dark Matter Day included an event in Parliament which was attended by a number of SNP MPs and several Lords. At the Department for Business, Energy and Industrial strategy a dark matter display attracted a steady stream of people including the Secretary of State for Business, Energy and Industrial Strategy, Greg Clark.

The UK’s universities where researchers are studying dark matter put on a multitude of events ranging from public lectures talks and art displays, to Halloween events with a dark matter twist and air hockey in the dark. The Dark Matter UK community was actively involved in organising many of those events.

STFC’s own laboratories also put on activities. At Daresbury Laboratory, families with young children attended a special Talking Science Lecture and family workshop. The UK Astronomy Technology Centre hosted a special public astronomy evening, including a presentation, tour and stargazing activities.

At Rutherford Appleton Laboratory, students made their own dark matter particles and had a live lesson in dark matter broadcast online from STFC’s Boulby Laboratory. 180 children took part.

Schools workshop at RAL.
(Credit: STFC)

Boulby Laboratory put on live links throughout the day, to Parliament and school children and they did a Facebook Live Q and A where pupils could have their questions answered. Teaching resources were shared with schools across the country and a competition for schoolchildren to have their artwork featured on the wall at Boulby’s new lab was launched on the day.

All in all, Dark Matter Day was a huge success, leaving behind a legacy of greater understanding of and appreciation for dark matter research and with many on the hashtag #darkmatterday on Twitter calling it the new Halloween!